Neuropsychological status of children treated for brain tumors: a critical review and integrative analysis.

The literature on the neuropsychological status of children with primary brain tumors was reviewed to identify English-language publications reporting the results of standardized, quantitative measures of patient function. The 22 studies that met these review criteria, representing 544 patients, were evaluated to assess the relationship between traditional risk factors (age at diagnosis, tumor location, radiation therapy, and time since completion of treatment), as well as subsequent intellectual development, academic achievement, psychosocial adjustment, and neuropsychological status. The impact of other potentially salient factors, such as seizures and sensory and motor deficits, was evaluated when possible. Despite inconsistent reporting of demographic and treatment-related effects across studies which precluded formal meta-analysis, we were able to confirm the primary importance of radiation therapy volume and age at treatment on IQ. No effects were detected for tumor location. Younger children treated with cranial (whole brain) irradiation showed a 14-point deficit in IQ as compared with their older counterparts. No significant differences were noted between older children receiving local or cranial irradiation, although both groups had IQ levels 12-14 points lower than those not irradiated. The high-risk groups identified in this study require increased clinical surveillance. Definitive evaluation of potential risk factors for neuropsychological impairment will depend on more complete reporting of relevant patient characteristics and interinstitutional studies.